Types of Evolution and Speciation Practice Test

Seven thousand years ago, a species of oryx indigenous to the Arabian Peninsula was separated when an earthquake caused an insurmountable barrier to form between different geological segments of the population. A recent population genetics study showed that the two populations were no longer able to successfully interbreed.

What type of speciation event does this information indicate?

Seven thousand years ago, a species of oryx indigenous to the Arabian Peninsula was separated when an earthquake caused an insurmountable barrier to form between different geological segments of the population. A recent population genetics study showed that the two populations were no longer able to successfully interbreed.

Careful testing of these two species found that a physiological change in one species was responsible for the mating incompatibility between the two populations. Which of the following answer choices best describes the nature of this mating incompatibility?